PREPARATION OF ULTRAFINE IRON PARTICLES USING AN RF PLASMA

Particles with a median size of about 10 nm were prepared by passing pure iron powders through an rf plasma. Growth took place in a fog state and a Brownian collison-coalescence mechanism governed the process. The particles solidified in the gamma -phase and transformed to alpha -phase. Particles less than 60 nm could be transformed into single crystals of alpha -phase, but single crystals rarely existed when the particle size was larger than 100 nm.